Expansion joints



Jan. 19, 1965 A. J. HlRs-r ETAL EXPANSION JOINTS 2 Sheets-Sheet 1 Filed June ll, 1962 Jan. 19, 1965 A. J. HlRsT ETAL 3,165,987

EXPANSION JOINTS Filed June 1l, 1962 2 Sheets-Sheet 2 3,165,987 EXPANSIDN JUINTS i Archie John Hirst andKazimierz Siwek, Leicester, and

Terrence John Potterton, 'Gien Parva, Leicester, England, assignors to Metalastilr Limited,fLeicester, Eng

land, a British company rtree teneri, 1962, sier. Ne. 261,485

claims priority, apparaten eine Britain, Mar. 19,1952,

masa/s2 l s claims. (ci. afiim This invention relates to expansion joints for accommodating the expansion of a'pair'of surfacing members which may be, foi-example, adjacent concrete road. sec-` tions or a road section joining v with a bridge surfacing.l section, the joint bridging an expansion gap between 'the surfacing members.

An object of Vthe present Vinvention is to provide an expansion joint comprising a' body of rubber, which term'.v

. faisant ?at'enied dan. 19, 1955 temperature condition, located betweenV a pairA of sur'- `facing 'members' which in theipresent example are, re-

spectively a concrete road surfacing section,findicated at it), and an adjacentfconcrete bridge surfacing section,V

indicatedV at 11. The expansion `joint,which is gener: ally indicated at 12, is positioned between the sections ill and 11, the joint bridging an expansiongap 14 for the kbridge structureibetweenfthe sections.

The joint comprises a pair of plate members 15,`each constituted by one limb of al1-angle sectioned metal member 16 having welded thereto metal reinforcing rods V1'7V cast into the adjacent concrete surfacing members, thereby attaching the members 16 to the surfacing members with ,l the-plate `members -lying in interfacing relationship is taken to include both rubber and rubber-like materif als, held always in a state of compression between the surfacing members so that the joint is sealed, thebody'; '-of rubber having an upper surface which remains at Y least substantially in theplane of the upperl surfaces of the surfacing members despite variations in the gap surface-remains aceeptably hat. l

Another object of the invention isso tojshap'e the rubwidth Ydue to change Vof temperature whereby the road ber bodyin cross-section that the body tends Vto buckle downwardly under the compressivetforces actingV upon it, and then to provide support means under the body and supporting the body against downward'buckling.

In vthis way the support means can be made to maintain the upper surface of the body. substantiallyin the plane of the upper surfacesof thesurfacing members at least within the normal rangeof ambient temperature conditions, the ow of rubber ofthe lrubber body necessary to accommodate narrowing of the expansion gap giving rise to a change of shape substantially only ofthe under surface of the rubber'body.V y

Another object of the inventionfis Yto provide an expansion joint as just described in which the support means supports the' rubber bodyin the mid-longitudinal 1 plane of the body at all times within the normal range of ambient temperature conditions, the depthof the rubber body in the mid-longitudinal plane of the body remaining'substantiallyuconstant, and the support means (accommodating bulging ofthe under surface of the rubber body, upon expansion of the surfacing members, to each side of the mid-longitudinalV plane of the body. Another object is so to construct -the expansion joint that the rubber'lbody is merely lodged in position be?V tween a'pair of metal plate members `defining the ex-1` one on each side of the expansion gapldgthe platemembers 15 thereby denin'g the expansion gap; Y ,l l

TheA members i6 are, cast into the adjacent surfacing' membersvduring assembly ofthe expansion joint, as will .l

hereinafter be described, with their other flanges 18 lying f flush with the general road surface to eachY sideof vthe joint.Y The flanges 1S have bolt holes 19 Vforfthe purpose v Likewise the anges 1 5v have aligning pairs of bolt holes 20 the purposeA of which will v hereinafterV described.

also hereinafter be described.V

The pairs of bolt holes 20 are providedrlspced apart-V in the .lengthwise direction Vof the joint asfshownin FIG. 2. Between each adjacent pair of V,boltfholes there is provided, welded .to one of the ilanges 15;,an angle- VVsectioned support member 23 upon which rests a rubber pansion gap, the body being located' in the vertical `div rection in the gapby intergengaging formations on the rubber vbodyan-:lthe-platernernbers respectively. f f

In this Way the Vuse lof anV extruded rubber section to now be described, merely by way of an example, with reference to the accompanying drawings in which:

FIG. lis a cross-section of a'n expansion joint according to the'present invention, l Y FIG. 2 is a plan View of the joint shown in'FIG. l, and including in chain-dotted outline parts usedfor asf rowing'of theexpansion gap lli'upon. expansion ofth surfacing Vmembers 10 and 11 is accommodatedfby the j Vbody 24 which under the greater,compressiveforces their tiallyrin the plane of the surfaces of the surfacing'm Vbns'iagmi411;* p'- body 274. The rubber body 24 has a convex undervsurface 25 and is, supported by the support member 23 in its mid-longitudinal plane 26 corresponding with the midlongitudinal-plane of the joint. j l j The body 24 has on each. side a longitudinally 'extend-V f 'ingr rectangular sectioned groove 27 .which receives- Va Aj rectangular* sectioned 7rod 2S welded to the adjacentv iiangelS.` `:These inter-engaging formations 27,23 locate Vthe body 24 in the vertical direction.v j 1 L 1 1 The' body 24 is held in a stated/compression between the flanges 15 under. all conditions withinilthe'normal -range of ambient temperatures forwhich'the expansionT andthe depth of the body in this plane is selected so that Y the centre of, pressure of the rubber body under the compression forces lies sufiiciently. low down; 'in "the"Y plane 26 forthe body always :to tend to buckledownwardly under the compressiveforces acting upon it. The rubber body is supported against the downward buckling however bythe support'membergZSf which is'positioned to maintain `the uppersurfacedil of the Vbody substan-g.`

acting upon'its bulges downwardly on each siderof its midlongitudinal plane 26 i.e.'into the spaces-and 34, and 7,-, there isvery little upward bulginggof the'surface 30 eri-` cept under'fextreme conditions o-f compressionduefto sembling the joint in positionl between a pair of surfacing members, and ,Y FIGS. 3 and 4 show stages in the'assernbly of the joint between the surfacingniembers.

The drawings show the expansion` joint, at a mean i.

theexpansiongap being closed Vto nearits maximum extent; VTo reduce the bulging of the surface Sd'under erf treme conditions, the surface V30 is slightly dished in its.`

free state as shown in FIG. 3."

v To reduce the compression stitinessof body 274 the Ywidth direction `of the gapjld, and therebywensure fthat the expansionjoint :does not transmit too large a force to theV bridge section under maximurncompress'ion, Vthe y bodyis provided in the present example withlongitdinal- VV l.

' .ornittedvor replaced by Va single cavity placed of the rubber body sectionE Y l Where'an internal cavity or'cavitics are proyidedthese must `be dimensionedrand arranged'sothat thetendency` j Vfor the Yrubber YYbodyftobuckle downwardlyunder the vcompression 'forces is 'maintainedi.e. the centre-of pres- Y The grooves 27 and therods ZSTm'ay bedispen-sed with?? body'24jbeingrbonded to the metalVv sure mustremain suticientlylow down; .Y

. if required, the rubber.

n bolts 38 entered through the y ZYpreviously described. Y Y i 1 v 1 The bolts 38 are drawn up to compress thelrubber bodyY v 24 to anYeXtentdepending upon'the z trnbientitemperature at which Vvthe Vexpansionjoint iswinstalledj` "Ih'efrbolts 37 Y are then tightened soas tohold therubbe'rbody incom; Y Vpression betweenpfthe members i6 Vand; the boltsYS are Yrentoved. Y

mid-longitudinal plane 26;

In some circumstances however these'cavities may be .Y Jhich is centrally members 16.

YThe surfacingmembersl andll are originallyrformerd j with rebates 412 which .togetherconstitute a trough tovref 1 ceive `the expansion joint as shown in FIG;V 4.V To assen?, K ble the joint, is made of clamping Ybars Yliindic'ated in EIGS. 2, 3 and=4.V The clamping bars are formed ,byf

angle-sectionedmembers, a number of which are provided,A v spaced apartginj, the lengthwisefdirection o f the joint, each bridgingthe joint andzbe'ing bolted to the members-16 ofy Y the jointby'bolts'indicatedlat 37 in FIGS.`Y2,-;3-and One Y of the bolt holes 39 for the'boltsi'in the clamping-bars' Y36 `isofelongated.form soas -to aliowrthe members-16 Ato be drawn towardsVV one kanothe'rfby. means VYof :further y Thefexpansion joint is then` Ytrough.v s

Y 'clamping bars vrrbridgingjthe troughgand supporting the.Y Y jointV in its correct positionwasslhownin FIGA. "shuttering plates` 3 0 are then inserted,V together Withfa Cop-VV per' strip" 1&3" to seal oftheV lower'sideo'f the gapvfjtgf n andthe space` around the""'oint is `then lledfwithzconcrete thereby ,to castthe jointintoj position., Einallyithewclampldiving bars36 are removed andthe bolt holesintheflangesv 1Sl illed with 'concrete or fanyother Vsuitablegiillin'gf'mate-f. Y rial.-l Thebopperstnipgmay beomitted ifjdesired; i" Y iQ QTheS free width A.of -the Y rubberbo'd'y .'inYY the joint new `being"desciiberlYby wayY of `eziairnple-s 3%1, TheImaX-Yf iinum compressionY` of the joint is\-three-quartersofjlan` inch fromthefree condition of thejointallowingjfor)a minimum of onegeighth of an Yinch.conqression under-the j idest gap dimensioned within thedesigned yambientstemaI 1 This allows fora contraction and Y'exinaansion of the joint.;

of plus-orfxninus'iive, sixteenths oan inchand'is therefore l suitable'xfor bridge" structures witha free lengthnpV tov bridge structure andV the' ambient temperaturejr'ange.

suitable` aligning pairs ofrboltrholes *Y the bridge structure in relationito the approachingiroad surfacewill not damage'Ythejoint. f Y, v s Y The rubber body, 24 and the'main metaliangle'mernbers 16 may be of `any convenientflength.V If the joint fis to, compriseV lengthwise sections Vfor convenience in manufac-r ture the` angle membersnfofthe sections are weided end toendfon thesite, andI if thel road surface is camberedl the camberisgaccomrnodated'in the weld connections 'Alternativelythe Ymetal members 16, the rods 28 andthe support member723maybe bowed to follow thegcamberl Y* of the road and either Vwelded upfromY shorter lengthsi or Y Y 'made each in one lengthwise piece.` Y We claim: x

1. An kexpansion joint Vaccommodating the Yexpansion i of apar of surfacing Vrr'ier'r'xbers, the fjointucomprisnga body of Yrubber confined between -and bridging, in load 'Y n carrying manner, an `e q2ansiongap betweenth'e-surrfac-Y 2 ing r`nernbers,Y the width .ofjthe Yexpansion gap being al-Y i Yfwaysless thantheunconiined width ofsaid body of rubber vwhereby thev body of jrubberV is heldalways ina state of1 o t compressionbetween thef'surfajcing members, said bodyY` s 'having a substantially plane upper;v surface -and a trans- .Y ,'fverselyconvex undersurface'so as toprese'nt YYarthiclniess in its mid-longitudinal planeVbetwec-ni` the surfacing-mem n ers Ywhichgis substantially greatenthan vits thickness in-V Y ,regionsfadjacent its longitmiinal edges whereby the Abody s f .tends always to buclileVY downwardly under the action of lthe .compression forc'esexerted vupnnitby the-surfging I members, andsupport means carriedfrom one ofthe sut-'1.

:facing membersf'and ,ej't'endingrbeneath Lthe rubberV body acrosstheexpansion,gap'towards Ytheother offkthe s ur`v f Yfacingnienib'erls; the support means'presentingajat'up.

wardly ldirected supportsurfaceflying tangentially irren-' Ygageifnent with the convex ILynclers'urface of the rubber body Y andisup'porting the-bodyjagainst' its downward buckling thesupport surface onfeachA side ofthe mid-.longitudinal plane or" thebvody soasuto deine therewith a space,said v I' spacesfaccommodating, downward bigllging` of theY undersurface ofthe rubberb'o'dy uponl eiqsa'nsionv of the-surfac- .451instmember?.V Y

l.the rubb'erfbod'y is an extruded sectionf having at least one i about` l5()Y feet depending upon thematevrialsuse'din the j c Due'to' ,the compression which isalways, maintained ,in f v Ytheg ubberbody 24,.,fthe1jint -eiecdtively seals the kgap in Y th-:road surface .underY allconditions' inclnding. the widestl jgapdimension, without verticalloadV on; thernbbei'Yr Y* f.

kbfody dneft'o V'traiiicQ Thel joint therefore reventsfwlater .-seepi'ng through'theprorad'sufaceinlto thefexpansionYgrap'.`Y Y Vj'he; joint doesgnotneessarily,haveftoibenassemblediexv Y actlyatrightangles'to the Vdirection oflthe `thernrial moye-Q ment which it is to accommodate since, it will permit smalti Y relative ylongitudinal movements between the members 16 therrubbjer body then beingdeflected inffshear;` .A'Vlfhrislis'orf vadvantagesince it meansthat the jointmaybe pusedwith:

andcheap to lp'roducetr Since there 'isY no direct metal'conV-j pplch) v 4 Y. Y

' c Vunder all conditions of joint and the joint furtherc'ofrn- .Y

prisingja support means carried by one ofthe plate.inem:v` Y

' expansion gap towardsthe otherrplate member, the supe;l

' .port. means presenting-'anat upwardly` directedV support longitudinally'extending internal cavity to reduce itsl coni-` Y pression stiffness*infthe' widthrdirectionof the' enpa'nsion t 3, 'Anexpansion joint accommodatingtheexpansionof' Y. afpair;k bfAA surfacing membersQthe joint Vcorriprising abody" ofrubberj confined between and bridging inload'carrying.,

fnianner anexpansio'n .gap formed between metal plate members carriedurptively.byitheirsurfacinggmembers; i Y the width4 ofgnthelgap Vbetvg/een .thefmetal A plate lmembers f being always less ,than thef funcontimed"width-of` said body :ofrrubber whereby the rubber body isA held al'waysin aYV staterof compression betwegenfthe metal' platememlner'-s',Y the f j rubberjbody being separateoftheplate.members and hav.- Y Ying a substantially plane upper surface V'and'a`thicknessin 'f1 frits;,miVdJ-longi'tndinamlV plane `which isfsubstantially greater thanitsthiclgnessin regions adjacent-its longitudinal edges,` f j 1 vwherebytheyvbody,tends alwaysto bucldedownwardly v @under theyaction'of the compres'sioxrforces exerted` upon it by thefplatelmermbers;theIlongitudinalfedges of the rubber "body beingfsupported Vvertically byinterengaging formations on the `bodyandthe plate members respectively surface :lyinggtangcntially `in engagement withthe underfsarracre ofthe rubber bpay in uijerjegipn 'or their;ifi-lang 2. YAn expansion ljointfasclainied vfin claim l1, wherein;

P, D tudinal plane of the body to support the body against its downward buckling tendency at all times within the range of normal ambient temperature conditions to be encountered, with the upper surface of the body lying substantially in the plane of the upper surfaces of the surfacing members, the undersurface of the rubber body on each side of, and in the supported region thereof lying clear of the support means part bounding a space, said spaces accommodating downward bulging of the undersurface of the rubber body upon expansion of the surfacing members.

4. An expansion joint accommodating the expansion of a pair of surfacing members, the joint comprising a body of rubber confined between and bridging in load carrying manner an expansion gap formed between metal plate members carried respectively by the surfacing members, the width of the gap between the metal plate members being always less than the unconfined width of said body of rubber whereby the rubberV body is held always in a state of compression between the metal plate members, the rubber body being bonded to the plate members and having a substantially plane upper surface and a thickness in its mid-longitudinal plane which is substanpending flanges of a pair of metal anglets'ectioned members cast respectively into thesurfacing members, the Width of the gap between said flanges being always less than the unconined width` of said body of rubber where-y by the rubber body is held always in a state of compression between said depending anges, the body of rubber v being formed as an extruded section having a substantially greater than its thicknes in regions adjacentits longin tudinal edges, whereby the body tends always to 'buckle downwardly under the action or" the `compression forces exerted upon it by the plate members, and a support means carried by one of the plate members and extending beneath the rubber body across the expansion gap towards the other of said plate members, the support means presenting a flat upwardly directed support surface lying tangentially in engagement with the undersurface of the rubber body in the region ofthe mid-longitudinal plane of the body to support the body against its downward buckling tendency at all times within the range of normal ambient temperature conditions to .be encountered, with the upper surface of the body lying substantially in the tially plane upper surface and a transversely convexV undersurface so as to present a thickness in its mid-longitudinal plane which is substantially greater than its thickness in regions adjacent in longitudinal edges, whereby the body tends always to buckle downwardly under the action of the compression forces exerted upon it by the depending flanges of the angle sectioned members, the longitudinal edges of the rubber body being supported vertically by inter-engaging formationsV onthe body and the depending flanges of the angle sectionedV members respectively under all conditions of the joint, the joint further comprising a further metal angle sectioned member connected With one flange at against the depending flange of one of the rst said angle sectioned members and with the other ange extending beneath the rubber body across the expansion gap towards the depending frange of the other of said first said angle sectionedv members, said other flangel presenting a flat upwardlydirected support surface l v lying tangentially in engagement with the convex under-jv Y surface of the body and supporting the rubber body against its downward buckling tendency at all times within` the plane of the upper surfaces of the surfacing members,y the carrying manner, an expansion gap formed between derange of normal ambient temperature conditions to be Y encountered with the upper surface of the body lying substantially in the plane of the upper surfaces of the sur-` facing members, the convexundersurfacelof the rubber body lying clear of the support'surface on each side of the mid-longitudinal plane of the body so as to define therewith a space, said spaces accommodating downward'bulging of the undersurface of the rubber body upon expansion of the surfacing members. f

f ReferencesCited in the tile ofithis patentV UNITED STATES PATENTS Y,

2,210,138 Bishop Aug. 6, 1940 2,240,787 Kinzer' May 6, 1941 2,269,449 Fischer Jan. 1?, 1942 2,575,247 lCarter Nov. 13, 195i` 2,976,782 Thom Mar. 28, 3,068,763 Harza Dec. 18, 1962 v 3,097,579 Fujihara July 16, 19763 

1. AN EXPANSION JOINT ACCOMMODATING THE EXPANSION OF A PAIR OF SURFACING MEMBERS, THE JOINT COMPRISING A BODY OF RUBBER CONFINED BETWEEN AND BRIDGING, IN LOD CARRYING MANNER, AN EXPANSION GAP BETWEEN THE SURFACING MEMBERS, THE WIDTH OF THE EXPANSION GAP BEING ALWAYS LESS THAN THE UNCONFINED WIDTH OF SAID BODY OF RUBBER WHEREBY THE BODY OF RUBBER IS HELD ALWAYS IN A STATE OF COMPRESSION BETWEEN THE SURFACING MEMBERS, SAID BODY HAVING A SUBSTANTIALLY PLANE UPPER SURFACE AND A TRANSVERSELY CONVEX UNDERSURFACE SO AS TO PRESENT A THICKNESS IN ITS MID-LONGITUDINAL PLANE BETWEEN THE SURFACING MEMBERS WHICH IS SUBSTANTIALLY GREATER THAN ITS THICKNESS IN REGIONS ADJACENT IS LONGITUDINAL EDGES WHEREBY THE BODY TENDS ALWAYS TO BUCKLE DOWNWARDLY UNDER THE ACTION TO THE COMPRESSION FORCES EXERTED UPON IT BY THE SURFACING MEMBERS, AND SUPPORT MEANS CARRIED FROM ONE OF THE SURFACING MEMBERS AND EXTENDING BENEATH THE RUBBER BODY ACROSS THE EXPANSION GAP TOWARDS THE OTHER OF THE SURFACING MEMBERS, THE SUPPORT MEANS PRESENTING A FLAT UPWARDLY DIRECTED SUPPORT SURFACE LYING TANGENTIALLY IN ENGAGEMENT WITH THE CONVEX UNERSURFACE OF THE TUBBER BODY AND SUPPORTING THE BODY AGAINST ITS DOWNWARD BUCKLING TENDENCY AT ALL TIMES WITHIN THE RANGE OF NORMAL AMBIENT TEMPERATURE CONDITIONS TO BE ENCOUNTERED, WITH THE UPPER SURFACE OF THE BODY LYING SUBSTANTIALLY IN THE PLANE OF THE UPPER SURFACES OF THE SURFACING MEMBERS, THE SUPPORT CONVEX UNDERSURFACE OF THE RUBBER BODY LYING CELAR OF THE SUPPORT SURFACE ON EACH SIDE OF THE MID-LONGITUDINAL PLANE OF THE BODY SO AS TO DEFINE THEREWITH A SPACE, SAID SPACED ACCOMMODATING DOWNWARD BULGING OF THE UNDERSURFACE OF THE RUBBER BODY UPON EXPANSION OF THE SURFACING MEMBERS. 